The Advanced Television Systems. Committee (ATSC) published a Digital Television Standard in 1995 as Document A/53, hereinafter referred to simply as “A/53” for sake of brevity. A/53 describes vestigial-sideband amplitude modulation of the radio-frequency carrier wave using an eight-level modulating signal, which type of over-the-air DTV broadcasting is called “8-VSB”. Efforts have been made to provide for more robust transmission of data over broadcast DTV channels without unduly disrupting the operation of so-called “legacy” DTV receivers already in the field. Robust transmission of data for reception by mobile and hand-held receivers is provided for in a Candidate Standard: ATSC Mobile DTV Standard published in June 2009, referred to hereinafter simply as “A/153” for sake of brevity, and incorporated herein by reference. A/153 is directed to transmitting ancillary signals in a time division multiplexing arrangement with 8-VSB DTV signals, which ancillary signals are designed for reception by mobile receivers and by hand-held receivers. The ancillary data employ internet protocol (IP) transport streams.